Turkish newspaper Fanatik have confirmed Newcastle United were yesterday present at the game between Fenerbahce and Galatasaray.
Earlier this week there were reports Newcastle United had plans to attend the Istanbul derby to get a lowdown on target Garry Rodrigues.
The game ended in a 0-0 draw, and the Cape Verde international played the whole 90 minutes.
Newcastle United had a €8m offer turned down by the Turkish side in the last window, following their previous attempts to sign the Cape Verde international last summer.
The Turkish media expect the English side to make another attempt to sign Rodrigues in the next transfer window, but it looks like the player will not come cheap.
Galatasaray president Mustafa Cengiz recently said he would listen to offers in the region of €30m for Rodrigues, meaning Newcastle United would have to break their transfer record.
Everton have also been linked with the attacker in recent weeks.